Model AA-1 Adjustable Arms Parts Listing A AA-1 Adjustable Armrest 2 Units Height Adjustment Button B M6x25mm Hex Screw 6 Units Chair Seat C Washer 6 Units STOP Tools Needed: Phillips Head Screwdriver Please read all instructions before assembly. Step 1: Turn Chair Seat upside down and place on a clean, non-abrasive surface.